CountdownMathGame Solver for a tutorial on the SSaurel's Channel

CountdownMathGame.java

package com.ssaurel.countdowngame;

import java.util.ArrayList;

public class CountdownGame {

  private static final Operation[] OPERATIONS = { new Add(), 
						 new Subtract(), 
						 new Multiply(), 
						 new Divide() };
  private ArrayList<String> solution = new ArrayList<>();

  public boolean findSolution(int[] t, int nb, int total) {
    for (int i = 0; i < nb; i++) {
      if (t[i] == total) {
        return true;
      }

      for (int j = i + 1; j < nb; j++) {
        for (int k = 0; k < OPERATIONS.length; k++) {
          int res = OPERATIONS[k].eval(t[i], t[j]);

          if (res != 0) {
            int savei = t[i], savej = t[j];
            t[i] = res;
            t[j] = t[nb-1];

            if (findSolution(t, nb- 1, total)) {
              solution.add(Math.max(savei, savej) + " " + 
			    OPERATIONS[k].symbol() + " " + 
			    Math.min(savei,  savej) + " = " + res);
              return true;
            }

            t[i] = savei;
            t[j] = savej;
          }
        }
     }
   }

    return false;
  }

  public void printSolution() {
    for (int i = solution.size() - 1; i >= 0; i--) {
      System.out.println(solution.get(i));
    }
  }
	
}